Interpretive Summary: Ornamental flowering cherry trees (Prunus L. species) are popular landscape plants, made famous in the U.S. by the historic Tidal Basin cherries planted in Washington, D.C. in 1912. Planted primarily for their spring bloom, flowering cherries are used as street or shade trees in commercial and residential landscapes, and are also valued for their fall foliage as well as ornamental bark. Approximately 1.2 million flowering cherry trees are sold each year in the U.S., with an estimated total sales of $32 million. The U.S. National Arboretum has an ongoing breeding program aimed at broadening the genetic base of ornamental cherry trees by developing new cultivars with disease and pest resistance, tolerance to environmental stresses, and superior ornamental characteristics. Previous releases from our program include Prunus ‘Dream Catcher’ and ‘First Lady’. This report documents our two newest releases, Prunus ‘Helen Taft’ and P. campanulata ‘Abigail Adams’. ‘Helen Taft’ was introduced in 2012 to commemorate the 100th anniversary of the Japanese gift of cherry trees planted around the Tidal Basin in Washington, D.C. The name recognizes the role that former First Lady Helen Taft played in this historic planting. ‘Abigail Adams’ was released in 2013 as germplasm to enable its use in breeding.

Technical Abstract:
The U.S. National Arboretum has an ongoing breeding program aimed at broadening the genetic base of ornamental cherry trees (Prunus species) by developing new cultivars with disease and pest resistance, tolerance to environmental stresses, and superior ornamental characteristics. This report documents our two newest releases, Prunus ‘Helen Taft’ (NA 61128, PI 664076) and P. campanulata ‘Abigail Adams’ (NA 69013, PI 667657). ‘Helen Taft’ resulted from a controlled hybridization made in 1981 using P. yedoensis and P. campanulata. It was selected for further evaluation and propagated in 1988, and sent to cooperators for evaluation in 1992. ‘Helen Taft’ was selected for its vigorous growth, large pale pink flowers, and ease of production. It is well-suited to container or field production, and will usually produce flowers two years after vegetative propagation. Because of its large size and somewhat spreading crown, ‘Helen Taft’ can be used as a small shade tree or specimen plant, street tree in residential or highway plantings, or a spring accent plant in larger residential, park, and commercial landscapes. Its vigorous growth, large pale pink flowers, and ease of production make it a valuable addition to ornamental cherry germplasm in the U.S. P. campanulata ‘Abigail Adams’ was observed by USDA botanist Roland Jefferson on a 1986 collecting trip to Taiwan. At Jefferson’s request, scions from this cultivated plant were sent to the U.S. by the Department of Forestry, Chinese Culture University, Yang-Ming-Shan, Taipei, Taiwan in 1987. Grafted plants were released to the U.S. National Arboretum from the USDA-ARS Plant Germplasm Quarantine Office in 1998. Since then, this accession has been used in multiple crosses as part of the flowering cherry breeding program at the U.S. National Arboretum. ‘Abigail Adams’ was selected for its dark pink semi-double flowers, which are rare for this species. Because it is not reliably cold-hardy in Washington, D.C., it has not been tested in the field, so data on plant growth rate, habit, and landscape performance are not available. ‘Abigail Adams’ was released primarily as germplasm. It can be propagated from juvenile softwood cuttings or by grafting; cutting propagation from mature plants can be challenging. Because it has fertile flowers, this selection may be valuable as breeding material for its early bloom, low chilling requirement, and adaptation to warmer climates, as well as its striking floral display.